The present invention relates to a floating magnetic head to be used by floating it slightly above a surface of a recording medium in a magnetic disk drive. Particularly, the present invention relates to a structure of a floating composite magnetic head having a metal magnetic thin film of a high-saturation magnetic flux density formed adjacent to a non-magnetic magnetic gap, which is suitable for recording and reproduction of a high coercive force recording medium.
As magnetic heads which are used for writing and reading information in a magnetic disk drive, there are floating magnetic heads having structures as disclosed in the U.S. Pat. No. 3,823,416 and the Japanese Patent Publication JP-B-57-569, for example. According to these floating magnetic heads, a magnetic head is structured by providing a magnetic gap at a trailing terminal portion of a slider which is made of a high permeability oxide magnetic material and a whole structure is constituted by a high permeability oxide magnetic material. These floating magnetic heads of the above constitution, however, have a problem that they cannot be properly applied for recording in a recording medium of high coercive force that has come to be used in the recent years to meet the requirement of high recording density, because these floating magnetic heads have a saturated magnetic flux density of around 5,000 Gauss for a ferrite which is a high permeability oxide magnetic material.
In order to solve the above problem, a magnetic head having a metal magnetic thin film of high saturation magnetic flux density formed on a gap-facing surface has also come to be used. In other words, this is a magnetic head having a metal magnetic thin film of high saturation magnetic flux density provided on only a surface facing the magnetic gap of a floating magnetic head, a slider and a magnetic core piece of which are constituted by soft-ferrite, as disclosed in the JP-A-58-14311, for example. However, the magnetic head having this improved structure still has a problem that it has a large inductance after a predetermined winding has been provided at an electromagnetic transducing section, causing a reduction in resonance frequency which makes recording and reproduction at a high frequency disadvantageous. The magnetic head of the above constitution has a high inductance because the whole of the magnetic head is constituted by a magnetic material.
Accordingly, in order to have a low inductance, it is considered desirable to have a small magnetic circuit. From this point of view, a floating composite magnetic head having such a structure that a magnetic core is buriedly fixed in a non-magnetic slider was first disclosed in the U.S. Pat. No. 3,562,444. The inventors of the present invention also proposed a desirable shape of a floating composite magnetic head having a magnetic core buried in a non-magnetic slider, in the Patent Gazette of JP-A-61-199219. This floating composite magnetic head is characterized in that, as compared with the floating magnetic head of the above description where the whole of the magnetic head is constituted by a magnetic material, the latter floating compound has lower inductance after a predetermined winding is provided in a electro-magnetism transducing section so that recording at a high frequency becomes advantageous.
Further, in order to obtain a floating composite magnetic head of low inductance which can sufficiently record on a recording medium of high coercive force, it is ideal to have such a structure that a Mn-Zn ferrite of high saturation magnetic flux density is used as a substrate of magnetic cores and the magnetic cores having a thin metal film magnetic material of high saturation magnetic flux density adjacent non-magnetic magnetic gap section are buried in a non-magnetic slider. As an example of this floating composite magnetic head, there is a one invented by the inventors of the present invention as disclosed in JP-A-60-154310.
On the other hand, as the magnetic head becomes more compact and thinner and the track becomes narrower to meet the requirement of higher capacity of magnetic recording, there occurs a problem of a smaller reproduction output of recording in the magnetic head. Therefore, in order to improve recording and reproducing characteristics, a magnetic head using a single crystal Mn-Zn ferrite is used in a VTR magnetic head, for example, as disclosed in JP-A-62-18968 and JP-A-56-163518.
That is, JP-A-62-18968 discloses a magnetic head which has two high permeability magnetic materials facing each other through a magnetic gap, at least one of said high permeability magnetic materials being made up of a single crystal Mn-Zn ferrite, the (110) plane of the single crystal Mn-Zn ferrite being almost in parallel with the surface on which a main magnetic path is formed, and an angle e between the &lt;100&gt; direction in the (110) plane and the surface forming the magnetic gap being in the range of 5.degree. to 40.degree. or 80.degree. to 120.degree., and in which glass is fused adhered to at least the surface of the high permeability magnetic material near the side of the magnetic gap, said glass having a compression factor lower than that of ferrite when temperature is reduced from the glass sticking temperature to the room temperature. JP-A-56-163518 discloses a magnetic head which is constituted in a similar manner as that of JP-A-62-18968 by using a single crystal Mn-Zn ferrite which has solid-soluted SnO.sub.2.